2,308 research outputs found
Chlamydia trachomatis infection and the risk of perinatal mortality in Hungary
Introduction: Chlamydial infections of the genital tract are thought to often lead to preterm birth, which is the most important perinatal problem in Hungary.
Aim of study: A multicenter study was carried out to determine the prevalence of Chlamydia trachomatis infection, risk factors for the infection and to relate the infection to perinatal mortality, accounting for potential confounding effects.
Methods: The nucleic acid hybridization method (PACE2 Gen-Probe) was applied for the examination of Chlamydia trachomatis. Logistic regression analysis was used to assess risk.
Results: A total of 6156 pregnant women were examined for the occurrence of Chlamydia trachomatis. The observed overall rate of chlamydial infection was 5.9%. Young age (less than 24 years old) (OR and 95% CI:1.6 (1.3-2.0)), unmarried status (1.5 (1.2-1.9)) and the high unemployment rate (2.1 (1.6-2.7)) were statistically significant predictors of the infection.
In logistic regression analysis, chlamydial infection (1.9 (1.1-3.3)). high unemployment rate (1.5 (1.2-2.2)) and low birth weight (1.7 (1.1-2.7) were significant predictors of perinatal mortality.
Conclusions: Testing pregnant women for diseases that can be transmitted perinatally is an important part of obstetric cart. Screening for C. trachomatis of unmarried women under 24 years of age is suggested and need increased observation during labor
Subcellular partitioning of MRP RNA assessed by ultrastructural and biochemical analysis.
A small RNA encoded within the nucleus is an essential subunit of a RNA processing endonuclease (RNase MRP) hypothesized to generate primers for mitochondrial DNA replication from the heavy strand origin of replication. Controversy has arisen, however, concerning the authenticity of an intramitochondrial pool of MRP RNA, and has called into question the existence of pathways for nucleo-mitochondrial transport of nucleic acids in animal cells. In an effort to resolve this controversy, we combined ultrastructural in situ hybridization and biochemical techniques to assess the subcellular partitioning of MRP RNA. Cryosections of mouse cardiomyocytes were hybridized with biotin-labeled RNA probes complementary to different regions of MRP RNA and varying in length from 115 to 230 nucleotides, followed by immunogold labeling. In addition, we transfected mouse C2C12 myogenic cells with constructs bearing mutated forms of the mouse MRP RNA gene and compared the relative abundance of the resulting transcripts to that of control RNAs within whole cell and mitochondrial fractions. In the former analysis we observed preferential localization of MRP RNA to nucleoli and mitochondria in comparison to the nucleoplasm and cytoplasm. In the latter series of studies we observed that wild-type MRP RNA partitions to the mitochondrial fraction by comparison to other RNA transcripts that are localized to the extramitochondrial cytoplasmic space (28S rRNA) or to the nucleoplasm (U1 snRNA). Deletions within 5' or 3' regions of the MRP RNA gene produced transcripts that remain competent for mitochondrial targeting. In contrast, deletion of the midportion of the coding region (nt 118 to 175) of the MRP RNA gene resulted in transcripts that fail to partition to the mitochondrial fraction. We conclude that an authentic intramitochondrial pool of MRP RNA is present in these actively respiring cells, and that specific structural determinants within the MRP RNA molecule permit it to be partitioned to mitochondria
Injectable laminin-functionalized hydrogel for nucleus pulposus regeneration.
Cell delivery to the pathological intervertebral disc (IVD) has significant therapeutic potential for enhancing IVD regeneration. The development of injectable biomaterials that retain delivered cells, promote cell survival, and maintain or promote an NP cell phenotype in vivo remains a significant challenge. Previous studies have demonstrated NP cell - laminin interactions in the nucleus pulposus (NP) region of the IVD that promote cell attachment and biosynthesis. These findings suggest that incorporating laminin ligands into carriers for cell delivery may be beneficial for promoting NP cell survival and phenotype. Here, an injectable, laminin-111 functionalized poly(ethylene glycol) (PEG-LM111) hydrogel was developed as a biomaterial carrier for cell delivery to the IVD. We evaluated the mechanical properties of the PEG-LM111 hydrogel, and its ability to retain delivered cells in the IVD space. Gelation occurred in approximately 20 min without an initiator, with dynamic shear moduli in the range of 0.9-1.4 kPa. Primary NP cell retention in cultured IVD explants was significantly higher over 14 days when cells were delivered within a PEG-LM111 carrier, as compared to cells in liquid suspension. Together, these results suggest this injectable laminin-functionalized biomaterial may be an easy to use carrier for delivering cells to the IVD
Detection of high-frequency oscillations by hybrid depth electrodes in standard clinical intracranial EEG recordings
High-frequency oscillations (HFOs) have been proposed as a novel marker for epileptogenic tissue, spurring tremendous research interest into the characterization of these transient events. A wealth of continuously recorded intracranial electroencephalographic (iEEG) data is currently available from patients undergoing invasive monitoring for the surgical treatment of epilepsy. In contrast to data recorded on research-customized recording systems, data from clinical acquisition systems remain an underutilized resource for HFO detection in most centers. The effective and reliable use of this clinically obtained data would be an important advance in the ongoing study of HFOs and their relationship to ictogenesis. The diagnostic utility of HFOs ultimately will be limited by the ability of clinicians to detect these brief, sporadic, and low amplitude events in an electrically noisy clinical environment. Indeed, one of the most significant factors limiting the use of such clinical recordings for research purposes is their low signal to noise ratio, especially in the higher frequency bands. In order to investigate the presence of HFOs in clinical data, we first obtained continuous intracranial recordings in a typical clinical environment using a commercially available, commonly utilized data acquisition system and "off the shelf" hybrid macro-/micro-depth electrodes. These data were then inspected for the presence of HFOs using semi-automated methods and expert manual review. With targeted removal of noise frequency content, HFOs were detected on both macro- and micro-contacts, and preferentially localized to seizure onset zones. HFOs detected by the offline, semi-automated method were also validated in the clinical viewer, demonstrating that (1) this clinical system allows for the visualization of HFOs and (2) with effective signal processing, clinical recordings can yield valuable information for offline analysis. © 2014 Kondylis, Wozny, Lipski, Popescu, DeStefino, Esmaeili, Raghu, Bagic and Richardson
Integrin-mediated interactions with extracellular matrix proteins for nucleus pulposus cells of the human intervertebral disc.
The extracellular matrix (ECM) of the human intervertebral disc is rich in molecules that interact with cells through integrin-mediated attachments. Porcine nucleus pulposus (NP) cells have been shown to interact with laminin (LM) isoforms LM-111 and LM-511 through select integrins that regulate biosynthesis and cell attachment. Since human NP cells lose many phenotypic characteristics with age, attachment and interaction with the ECM may be altered. Expression of LM-binding integrins was quantified for human NP cells using flow cytometry. The cell-ECM attachment mechanism was determined by quantifying cell attachment to LM-111, LM-511, or type II collagen after functionally blocking specific integrin subunits. Human NP cells express integrins β1, α3, and α5, with over 70% of cells positive for each subunit. Blocking subunit β1 inhibited NP cell attachment to all substrates. Blocking subunits α1, α2, α3, and α5 simultaneously, but not individually, inhibits NP cell attachment to laminins. While integrin α6β1 mediated porcine NP cell attachment to LM-111, we found integrins α3, α5, and β1 instead contributed to human NP cell attachment. These findings identify integrin subunits that may mediate interactions with the ECM for human NP cells and could be used to promote cell attachment, survival, and biosynthesis in cell-based therapeutics
Motivated proteins: a web application for studying small three-dimensional protein motifs
<b>BACKGROUND:</b> Small loop-shaped motifs are common constituents of the three-dimensional structure of proteins. Typically they comprise between three and seven amino acid residues, and are defined by a combination of dihedral angles and hydrogen bonding partners. The most abundant of these are alphabeta-motifs, asx-motifs, asx-turns, beta-bulges, beta-bulge loops, beta-turns, nests, niches, Schellmann loops, ST-motifs, ST-staples and ST-turns.We have constructed a database of such motifs from a range of high-quality protein structures and built a web application as a visual interface to this. <b>DESCRIPTION:</b> The web application, Motivated Proteins, provides access to these 12 motifs (with 48 sub-categories) in a database of over 400 representative proteins. Queries can be made for specific categories or sub-categories of motif, motifs in the vicinity of ligands, motifs which include part of an enzyme active site, overlapping motifs, or motifs which include a particular amino acid sequence. Individual proteins can be specified, or, where appropriate, motifs for all proteins listed. The results of queries are presented in textual form as an (X)HTML table, and may be saved as parsable plain text or XML. Motifs can be viewed and manipulated either individually or in the context of the protein in the Jmol applet structural viewer. Cartoons of the motifs imposed on a linear representation of protein secondary structure are also provided. Summary information for the motifs is available, as are histograms of amino acid distribution, and graphs of dihedral angles at individual positions in the motifs. <b>CONCLUSION:</b> Motivated Proteins is a publicly and freely accessible web application that enables protein scientists to study small three-dimensional motifs without requiring knowledge of either Structured Query Language or the underlying database schem
Changes in midbrain pain receptor expression, gait and behavioral sensitivity in a rat model of radiculopathy.
Intervertebral disc herniation may contribute to inflammatory processes that associate with radicular pain and motor deficits. Molecular changes at the affected dorsal root ganglion (DRG), spinal cord, and even midbrain, have been documented in rat models of radiculopathy or nerve injury. The objective of this study was to evaluate gait and the expression of key pain receptors in the midbrain in a rodent model of radiculopathy. Radiculopathy was induced by harvesting tail nucleus pulposus (NP) and placing upon the right L5 DRG in rats (NP-treated, n=12). Tail NP was discarded in sham-operated animals (n=12). Mechanical allodynia, weight-bearing, and gait were evaluated in all animals over time. At 1 and 4 weeks after surgery, astrocyte and microglial activation was tested in DRG sections. Midbrain sections were similarly evaluated for immunoreactivity to serotonin (5HT(2B)), mu-opioid (µ-OR), and metabotropic glutamate (mGluR4 and 5) receptor antibodies. NP-treated animals placed less weight on the affected limb 1 week after surgery and experienced mechanical hypersensitivity over the duration of the study. Astroctye activation was observed at DRGs only at 4 weeks after surgery. Findings for pain receptors in the midbrain of NP-treated rats included an increased expression of 5HT(2B) at 1, but not 4 weeks; increased expression of µ-OR and mGluR5 at 1 and 4 weeks (periaqueductal gray region only); and no changes in expression of mGluR4 at any point in this study. These observations provide support for the hypothesis that the midbrain responds to DRG injury with a transient change in receptors regulating pain responses
Photoreduction of Shewanella oneidensis Extracellular Cytochromes by Organic Chromophores and Dye-Sensitized TiO2.
The transfer of photoenergized electrons from extracellular photosensitizers across a bacterial cell envelope to drive intracellular chemical transformations represents an attractive way to harness nature's catalytic machinery for solar-assisted chemical synthesis. In MR-1 (MR-1), trans-outer-membrane electron transfer is performed by the extracellular cytochromes MtrC and OmcA acting together with the outer-membrane-spanning porincytochrome complex (MtrAB). Here we demonstrate photoreduction of solutions of MtrC, OmcA, and the MtrCAB complex by soluble photosensitizers: namely, eosin Y, fluorescein, proflavine, flavin, and adenine dinucleotide, as well as by riboflavin and flavin mononucleotide, two compounds secreted by MR-1. We show photoreduction of MtrC and OmcA adsorbed on Ru-dye-sensitized TiO nanoparticles and that these protein-coated particles perform photocatalytic reduction of solutions of MtrC, OmcA, and MtrCAB. These findings provide a framework for informed development of strategies for using the outer-membrane-associated cytochromes of MR-1 for solar-driven microbial synthesis in natural and engineered bacteria.This work was supported by the UK Biotechnology and Biological Sciences Research Council (grants BB/K009753/1, BB/K010220/1, BB/K009885/1, and BB/K00929X/1), the Engineering and Physical Sciences Research Council (EP/M001989/1, PhD studentship 1307196 to E.V.A.), a Royal Society Leverhulme Trust Senior Research Fellowship to J.N.B., the Christian Doppler Research Association, and OMV group
Representations of sport in the revolutionary socialist press in Britain, 1988–2012
This paper considers how sport presents a dualism to those on the far left of the political spectrum. A long-standing, passionate debate has existed on the contradictory role played by sport, polarised between those who reject it as a bourgeois capitalist plague and those who argue for its reclamation and reformation. A case study is offered of a political party that has consistently used revolutionary Marxism as the basis for its activity and how this party, the largest in Britain, addresses sport in its publications. The study draws on empirical data to illustrate this debate by reporting findings from three socialist publications. When sport did feature it was often in relation to high profile sporting events with a critical tone adopted and typically focused on issues of commodification, exploitation and alienation of athletes and supporters. However, readers’ letters, printed in the same publications, revealed how this interpretation was not universally accepted, thus illustrating the contradictory nature of sport for those on the far left
WNT signaling regulates self-renewal and differentiation of prostate cancer cells with stem cell characteristics
Prostate cancer cells with stem cell characteristics were identified in human prostate cancer cell lines by their ability to form from single cells self-renewing prostaspheres in non-adherent cultures. Prostaspheres exhibited heterogeneous expression of proliferation, differentiation and stem cell-associated makers CD44, ABCG2 and CD133. Treatment with WNT inhibitors reduced both prostasphere size and self-renewal. In contrast, addition of Wnt3a caused increased prostasphere size and self-renewal, which was associated with a significant increase in nuclear Β-catenin, keratin 18, CD133 and CD44 expression. As a high proportion of LNCaP and C4-2B cancer cells express androgen receptor we determined the effect of the androgen receptor antagonist bicalutamide. Androgen receptor inhibition reduced prostasphere size and expression of PSA, but did not inhibit prostasphere formation. These effects are consistent with the androgen-independent self-renewal of cells with stem cell characteristics and the androgen-dependent proliferation of transit amplifying cells. As the canonical WNT signaling effector Β-catenin can also associate with the androgen receptor, we propose a model for tumour propagation involving a balance between WNT and androgen receptor activity. That would affect the self-renewal of a cancer cell with stem cell characteristics and drive transit amplifying cell proliferation and differentiation. In conclusion, we provide evidence that WNT activity regulates the self-renewal of prostate cancer cells with stem cell characteristics independently of androgen receptor activity. Inhibition of WNT signaling therefore has the potential to reduce the self-renewal of prostate cancer cells with stem cell characteristics and improve the therapeutic outcome.Peer reviewe
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